Intermetallic layers and coatings are often formed on a surface of a metal component to protect the underlying metal substrate of the component and to extend its useful life during operation. For example, many superalloy components in gas turbine engines, like turbine blades, vanes, and nozzle guides, include an aluminide coating on airflow surfaces that protects the underlying superalloy base metal from high temperature oxidation and corrosion. Among other applications, gas turbine engines are used as aircraft or jet engines, such as turbofans. Gas turbine engines are also used in electromotive power generation equipment, such as industrial gas turbine engines, to generate electricity, and as power plants providing motive forces to propel vehicles.
Generally, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel, such as jet fuel or natural gas, and igniting the mixture, and a turbine blade assembly for producing power. In particular, gas turbine engines operate by drawing air into the front of the engine. The air is then compressed, mixed with fuel, and combusted. Hot exhaust gases from the combusted mixture pass through a turbine, which causes the turbine to spin about an axial center and thereby powers the compressor. Aircraft gas turbine engines, referred to herein as jet engines, propel the attached aircraft in response to the thrust provided by the flow of the hot exhaust gases from the gas turbine engine. Rotation of the turbine in industrial gas turbine engines generates electrical power and motive power for vehicles.
Gas turbine engines include turbine blades shaped as airfoils and coupled to the turbine. The hot exhaust gases from the combustor flow over and under each turbine blade. Because of the airfoil shape, the flow path across the top of the airfoil or convex side is much longer than the flow path underneath the concave side of the turbine blade. The result is an aerodynamic lift, which drives each of the turbine blades in the desired direction. Work is then extracted from the coordinated rotation of the turbine blades about the axial center of the gas turbine.
Conventional approaches for optimizing aerodynamic lift generated by the spinning turbine blades rely on increasingly radical airfoil shapes and three-dimensional topologies. However, these conventional approaches that focus solely upon advances in component geometry introduce complexity into the component manufacture process and are ultimately limited in the improvement in aerodynamic efficiency.
Accordingly, there is a need for gas turbine engine components with improved lift and methods of forming such gas turbine engine components that avoids the necessity of a complex airfoil shape.